Deep-subthreshold eta and pi(0) production probing pion dynamics in the reaction Ar+Caat 180A MeV

Authors
Martinez, G Charbonnier, Y Aphecetche, L Delagrange, H Gudima, KK Matulewicz, T Ploszajczak, M Schutz, Y Toneev, V Turrisi, R Appenheimer, M Metag, V Novotny, R Stroher, H Wolf, AR Wolf, M Weiss, J Averbeck, R Hlavac, S Holzmann, R Lefevre, F Simon, RS Stratmann, R Wissmann, F Hoefman, M van Goethem, MJ Lohner, H Ostendorf, RW Siemssen, RH Vogt, P Wilschut, HW Diaz, J Marin, A Kugler, A Tlusty, P Wagner, V Doppenschmidt, A
Citation
G. Martinez et al., Deep-subthreshold eta and pi(0) production probing pion dynamics in the reaction Ar+Caat 180A MeV, PHYS REV L, 83(8), 1999, pp. 1538-1541
Citations number
27
Categorie Soggetti
Physics
Journal title
PHYSICAL REVIEW LETTERS
ISSN journal
00319007 → ACNP
Volume
83
Issue
8
Year of publication
1999
Pages
1538 - 1541
Database
ISI
SICI code
0031-9007(19990823)83:8<1538:DEAPPP>2.0.ZU;2-M
Abstract
We report on a measurement of subthreshold eta and pi(0) mesons in the reac tion Ar + Ca at 180A MeV. We find that the ratio of the eta to pi(0) meson- production cross section is more than a factor of 20 smaller than the one e xpected from threshold-energy scalings of meson production. In addition, th e multiplicity of high m(t) pi(0) increases faster with the centrality of t he reaction than the multiplicity of the bulk of pi(0) mesons. This behavio r is explained by the rescattering of pi mesons in nuclear matter at the or igin of most energetic particles.